The present technology relates to an image processing device and method for processing an image signal and in particular to a technology field for reducing image quality degradation which may occur when a compressed image signal is decompressed and/or when gradation-dependent correction (a correction process in which the amount of correction varies among luminance gradations), such as gamma correction, is performed on the decompressed image signal.
In the field of image processing, an image is compressed to reduce the amount of image data. Examples of typical image compression methods include differential pulse-code modulation (PCM). With respect to differential PCM, it is known that when there is a large difference in luminance between adjacent pixels, the luminance errors are increased. As seen above, a luminance error typically occurs when an image is compressed.
Hereafter, a luminance error which occurs when an image is compressed (a luminance error caused by compression or decompression) will be referred to as a “compression error”.
Image display devices include ones which perform gradation-dependent correction on the basis of characteristics of the display panel, or the like. The gradation-dependent correction refers to a correction process in which the amount of correction varies among luminance gradations and is, for example, a gamma correction process.
Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2008-503185 discloses a display system which performs gamma correction.